The actors will feature alongside Viola Davis, Betty White, Michelle Williams and Zooey Deschanel in 'Letters to Jackie', reported E! online.
In the documentary, the stars read out 20 of the more than 800,000 condolence messages sent to the former First Lady Jacqueline Kennedy following the politician's tragic shooting in Dallas, Texas in 1963.
The film, directed by Bill Couturie, will premiere at the Kennedy Presidential Library in Boston, Massachusetts on September 17.